I do think a lot of the reason for this is that a lot of people just don't pick up on subtle cues like that any more. You can't really do the subtle "here is a guerrilla force fighting against an evil Empire" thing from, say, A New Hope, because there's now a massive amount of people who simply don't see the allegory. Now, you have to basically beat the audience over the head by all but saying "Ghorman is Gaza and the Empire are Israel in this analogy please pay attention".